Monochlorotetrafluorobenzene compounds

ABSTRACT

3-Chloro-2,4,5,6-tetrafluoro- Beta -hydroxyethylbenzene is a precursor to 3-chlorotetrafluorostyrene which can be homopolymerized or copolymerized with styrene to obtain coating compositions.

United States Patent 11 1 Pierce et al.

MONOCHLOROTETRAFLUOROBENZE NE COMPOUNDS Inventors: Ogden R. Pierce; John R. Greenwald, both of Midland, Mich.

Assignee: Dow Corning Corporation, Midland,

Mich.

Filed: Aug. 27, 1970 Appl. No.: 67,616

[ 51 Jan. 30, 1973 [56] References Cited UNITED STATES PATENTS 3,046,313 7/1962 Pummer et al. ..260/650 F 3,412,162 11/1968 Musgrave 3,511,883 5/1970 Bergomi ..260/650 F [57] ABSTRACT 3-Chloro-2,4,5,6-tetrafluoro-B-hydroxyethylbenzene is a precursor to 3-chlorotetraflu0rostyrene which can be homopolymerized or copolymerized with styrene to obtain coating compositions.

1 Claim, No Drawings MONOCHLOROTETRAFLUOROBENZENE COMPOUNDS The invention herein described was made in the course of, or under, a contract or subcontract thereunder with the United States Air Force.

This invention relates to functional monochlorotetrafluorobenzene compounds. In one aspect, the invention is directed to 3-chlorotetrafluorostyrene. In another aspect, the invention relates to vinyl polymers containing pendent chlorotetrafluorophenyl substituents.

In accordance with the invention there are provided compounds of the general formula free-radical catalysts, such as peroxides, to obtain vinyl-type addition polymers. Thus, the invention also provides vinyl polymers containing at least one unit of the formula The polymers can be homopolymers in which essentially all of the units are of the above-described formula or they can be copolymers formed by polymerization with other vinyl monomers such as styrene, acrylonitrile and butadiene. The fluorinated polystyrene is a hard rigid polymer and can be molded or applied as a protective coating to various substrates, such as metal or wood. When copolymerized with butadiene, an elastomer having a high fluorine content is obtained. A rubbery polymer of 25 mol percent and 75 mol percent units will have better solvent resistance than its nonfluorinated SBR analog.

The following examples are illustrative and not to be construed as limiting of the invention which is delineated in the claims.

EXAMPLE 1 A Grignard reaction was initiated by adding approximately 0.5 ml. of methyl iodide to l2.5 grams of magnesium in ml. of tetra hydrofuran. 1,3-Chloro- 2,4,5,6-tetrafluorobenzene (55 grams in 200 ml. of ether) was added at such a rate as to maintain the Grignard reaction temperature below 35C. After the addition was complete, 150 mls. of ether and 200 mls. of tetrahydrofuran and the mixture was stirred overnight. The Grignard reagent was cooled and ethylene oxide was added in incremental amounts. After 25 grams of ethylene oxide had been added, the reaction mixture was stirred for about 16 hours. Dilute hydrochloric acid (200 mls.) was added to the reaction mixture and the organic and aqueous phases were separated. The ether layer was washed with water and concentrated by distillation of the solvent. The residue was fractionated under reduced pressure to yield 23.5 grams of 3-chloro-2,4,5,G-tetrafluoro-B-hydroxyethylbenzene with a boiling point of 7679C./ 1 mm Hg. Analysis: Calculated for C l-I ClF O; C, 42.0; H, 2.18; F, 33.2

Found: C, 42.2; H, 2.36; F, 33.4.

EXAMPLE 2 3-Chloro-2,4,5,6-tetrafluoro-B-hydroxyethylbenzene (135 grams) was added to grams of P 0 and the mixture was heated to 160C. Hydroquinine was added. The volatile material was removed under vacuum and fractionated to obtain 52.7 grams of 3-chloro-2,4,5,6- tetrafluorostyrene which had a boiling point of 7375 C./20 mm Hg. The'proposed structure was confirmed by mass spectral and n.m.r. data.

EXAMPLE 3 Six grams of 3-chlorotetrafluorostyrene was placed in a test and a few crystals of 2,2 azobis(2-methyl propionitrile) were added. The mixture was heated for 3 hours at 132C. The solid polymer was removed by breaking the test tube. The polymer was soluble in acetone and methylene chloride. It was softened by, but not soluble in benzene. A solution (approximately 20 percent solids in methylene chloride) of the polymer was coated onto an aluminum panel and dried to obtain a 6 mil thickness. The coating adhered strongly to the metal and had a pencil hardness of F. An unsupported film of the polymer had self-extinguishing characteristics when exposed to an open flame.

EXAM PLE 4 azobis-(Z-methyl propionitrile) was heated in a test tube for 16 hours at 132C. A solid polymer was obtained. A portion of the polymer was dissolved in benzene and the solution applied to an aluminum panel. After drying the film adhered strongly to the panel and had a pencil hardness of F.

Reasonable modification and variation are within the scope of the present invention which is directed to monochlorotetrafluorobenzene compounds and vinylic polymers prepared therefrom.

That which is claimed is:

1. A compound of the formula 

